/*
* Copyright(c) 2017 Daniel Knüttel
*/

/* This program is free software.
* Anyways if you think this program is worth it
* and we meet shout a drink for me.
*/


/*    This program is free software: you can redistribute it and/or modify
*    it under the terms of the GNU Affero General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*    Dieses Programm ist Freie Software: Sie können es unter den Bedingungen
*    der GNU Affero General Public License, wie von der Free Software Foundation,
*    Version 3 der Lizenz oder (nach Ihrer Wahl) jeder neueren
*    veröffentlichten Version, weiterverbreiten und/oder modifizieren.
*
*    Dieses Programm wird in der Hoffnung, dass es nützlich sein wird, aber
*    OHNE JEDE GEWÄHRLEISTUNG, bereitgestellt; sogar ohne die implizite
*    Gewährleistung der MARKTFÄHIGKEIT oder EIGNUNG FÜR EINEN BESTIMMTEN ZWECK.
*    Siehe die GNU Affero General Public License für weitere Details.
*
*    Sie sollten eine Kopie der GNU Affero General Public License zusammen mit diesem
*    Programm erhalten haben. Wenn nicht, siehe <http://www.gnu.org/licenses/>.
*/


#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<termios.h>
#include <sys/select.h>
#include<signal.h>

#include"input_output.h"
#include"playfield.h"


int difficulty = 200;
static struct termios oldt, newt;
char  * playfield;
char ** horizon;

// break the mainloop, if there was a SIGINT
static volatile char sigint_received = 0;
static struct termios oldt, newt;

int main(void)
{

	// set up the terminal for our hacky game....

	tcgetattr(STDIN_FILENO, &oldt);
	newt = oldt;
	newt.c_lflag &= ~(ICANON | ECHO);
	tcsetattr(STDIN_FILENO, TCSANOW, &newt);

	// ok done

	int pos = 0;


	unsigned long long int score = 0;

	char input = KEY_DEFAULT;
	int to_place = 0;
	printf("q: end; d: right; a: left\n\n\n");

	while(input != KEY_EXIT && !(EOF_received || sigint_received))
	{
		horizon_drop_one_line(horizon);
		// clear both the cursor and
		// the last enemy
		playfield[pos] = ' ';
		horizon[0][to_place] = ' ';

		// actually if...else produces
		// smaller objectcode than switch
		if(input == KEY_RIGHT)
		{
			pos++;
			if(pos >= WIDTH)
			{
				pos = 0;
			}
		}
		if(input == KEY_LEFT)
		{
			pos--;
			if(pos < 0)
			{
				pos = WIDTH - 1;
			}
		}
		if(input == KEY_EXIT)
		{
			break;
		}
		clear_screen();
		
		print_horizon(horizon);

		// set the player cursor
		playfield[pos] = CHAR_ME; 

		// add the next enemy
		to_place = (random() & 0xff) % WIDTH;
		horizon[0][to_place] = CHAR_ENEMY;
		put_line(playfield);

		// player got hit.
		if(horizon[LINES - 1][pos] == CHAR_ENEMY)
		{
			printf("GAME OVER!\nYour score was: %llu\n", score);
			break;
		}
		usleep(difficulty * 1000);
		score++;

		if(!(score % 50))
		{
			difficulty--;
		}
		if(score == 0)
		{
			printf("Congrats. You won the game.\n");
			break;
		}

		printf("SCORE: %llu\n", score);

		// check this to prevent blocking
		if(EOF_received || sigint_received)
		{
			break;
		}
		input = get_last_key_or_default();
	}
	return 0;
}


// We need those signal handlers to
// free the memory properly.
// If they do not get caught the
// destructors will be skipped.
// should not happen.
void __attribute__((cold)) handle_sigint(int signum)
{
	sigint_received = 1;
}
// should not happen.
void __attribute__((cold)) handle_sigterm(int signum)
{
	printf("\n\nTERMINATED!\n");
	exit(1);

}

/*
Constructor: Add a sighandler for SIGINT and SIGTERM
 */
void __attribute__((constructor)) add_signal_handlers(void)
{
	signal(SIGINT, handle_sigint);
	signal(SIGTERM, handle_sigterm);
}

/*
Destructor: Free memory 
 */
void __attribute__((destructor)) clean(void)
{
	free(playfield);
	delete_horizon(horizon);

	tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
	printf("\n");
}

/*
Constructor: create all the data we need
 */
void __attribute__((constructor)) build_playfield(void)
{
	playfield = allocate_playfield(WIDTH);
	build_horizon(&horizon);
}